Steam-turbine



H. 'L. GUY.

STEAM TURBINE.

APPLICATION FILD NOV-16, 19H

1,379,258. Patented May 24,1921.

Fig.1 I

INVENTOR UNITED STATES PATENT OFFICE.

HENRY LEWJLS GUY, OF MANCHESTER, ENGLAND, ASSIGNOR TO THE BRITISH WEST- INGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A COMPANY OF GREAT BRITAIN.

STEAM-TURBINE.

Specification of Letters Patent.

Patented May 24, 1921.

Application filed November 16, 1918. Serial No. 262,877.

To all whom it may concern:

Be it known that I, HENRY LEWIS GUY, a subject of the King of Great Britain, and a resident of Manchester, in, the county of Lancaster, England, have invented a new and useful Improvement in Steam-Turbines, of which the following is a specification.

This invention relates to removable nozzle boxes for steam turbines and more particularly to nozzle boxes of the kind described in United States Patents, Nos. 1,286,204, filed J an. 81, 1917, and 1,325,135, filed Feb. 18, 1918, and application for United States patent, Serial No. 217,947, filed Feb. 18,1918.

The nozzle boxes described in said specifications take the form of elongated hollow chambers adapted to be located within and attached to the cylinder or a part secured thereto. In order "that the relative position of the nozzles of the nozzle box with respect to the moving blades or" the turbine with which they cooperate may be maintained substantially constant notwithstanding movements of the nozzle box due to expansion, guiding means are provided which permit movement of the box to take place only in a plane perpendicular to the turbine axis.

The present invention has for its object to provide a nozzle box of the aforementioned kind so constructed that means for guiding movement of the nozzle box, due to expansion, may if desired be dispensed with. This is accomplished, according to the present invention, by providing the nozzle box with a stiffening rib or ribs or by increasing the thickness of its Walls at parts so located that the box when in position within the turbine will have greater flexibility in a plane perpendicular to the turbine axis than in a plane parallel thereto In this way movement of the nozzle box due to expansion will take place more readily in a plane perpendicular to the turbine shaft and movement of the box and consequently of the nozzles toward or away from the moving blades will be substantially eliminated.

The invention is illustrated in the accompanying drawing in which Figure l is a partly sectional view of the high pressure end of a steam turbine having nozzle boxes located therein constructed in accordance with the invention and Figs. 2-5, inclusive,

, are detail views thereof more particularly hereinafter explained, Figs. 2 and 3 being taken along the lines 22 and 3-3, respectively, of Fig. 1.

In the drawing the turbine cylinder is indicated at 6 in the upper half of which is causing movement of the same, due to expansion, to take place in a plane perpendicular to said axis, the position which the box will assume when expanded being indicated in dotted lines. 7

The nozzle box 9 located in the lower half of the cylinder has its outer wall, 91. a, the wall opposite the nozzle openings 10increased in thickness as shown in Fig. 3, which will cause movements of the box, due to expansion, to take place in a plane perpendicular to the turbine axis as indicated by the dotted lines.

With nozzle boxes constructed as described above, although guiding means of the kind hereinbefore referred to may be dispensed with, it may in some case'sbe found desirable to provide suitable restraining means for preventing movement of the nozzle box in the axial direction of the turbine. Two forms which may conveniently be adopted are illustrated in Figs. 1, i and 5 of the drawing and comprise one or more lugs or projections 11 on the turbine cylinder, another lug or projection 12 on the nozzle box, and a pin 13 passing through said lugs. The position of the pin 13 is such that movement of the box, due to expansion, will be a rotary one around said pin. It will thus be seen that the restraining means takes the form of a hinge betweenthe turbine cylinder and the nozzle box.

Although the invention is illustrated here in as applied to the forms of nozzle box more particularly described in the specification of patent application Serial No.'

be applied to any form of nozzle box constructed in accordance with any of the patent applications hereinbefore recited.

2. In combination in a steam turbine, a

nozzle box so supported from the turbine case that it is free to expand and contract substantially independently of the case, and stiffened longitudinally thereof so that the box will have greater flexibility in a plane perpendicular to the turbine axis than 111 a plane parallel thereto when the box is in 7 place within turbine case. p 3-. In combination in a steam turbine, a nozzle box so supported from the turbine case that it is substantially free to expand or contract independently of the case and so stiffened as to resist deflection in planes other than in a plane at right angles to the axis of the turbine. v V

4L 'A nozzle block as set forth in claim 3 provided with restraining means for preventing movement thereof in the axial direction with relation to the case comprising a pivotal connection at or near the outer end thereof, the axial position of which .is such that the novement of the boxdue to expansion or contraction will be a rotary one 7 around the axis of said connection, substantially as described. 7

5. In combination in a steam turbine, an elongated nozzle box supported on the turbine case at a point intermediate the ends of thebox. and stiffened longitudinally, so that the box will have greater flexibility in a contraction will be a rotary one around said pivotal connection, substantially as described.

7. In combination with a turbine, a nozzle-box secured to the turbine case so that an end thereof is substantially free to expand independently of the case, and a stiffening rib extending longitudinally'of said free end and so located with relation to the box that V the free end thereof will have greater flexibility in a plane perpendicular to the turbine axis than in a plane parallel thereto, when the box is in place on the turbine case.

8. In combination with a turbine, a rdmovable nozzle box having a longitudinally extending stiffening rib and rigidly secured to the case at a point intermediate the ends of the box, said stiffeningrib being so located that the box when in place in the tur bine will have greater flexibility in aplane perpendicular to the turbine axis than in a plane parallel thereto.

9. A nozzle box as set forth in claim 8 in which a pivotal connection is Provided be- 

